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Reverberation is the main background interference in active sonar and seriously interferes with the extraction of the target echo. Active sonar systems can use short-pulse continuous wave (CW) signals to reduce the reverberation intensity. However, as the pulse width of the CW signals decreases, the reverberation envelope exhibits a high-frequency oscillating phenomenon. Active sonar often uses the cell average constant false alarm ratio (CA-CFAR) method to process the reverberation, which steadily decays with transmission distance. However, the high-frequency oscillation of the reverberation envelope deteriorates the performance of CA-CFAR, which causes a higher false alarm rate. To tackle this problem, the formation mechanism of the high-frequency oscillation characteristics of the reverberation envelope of the short-pulse-width CW signals is modeled and analyzed, and on this basis, an α filter is designed to suppress the high-frequency oscillation of the reverberation envelope before applying CA-CFAR. The simulation and lake trial results indicate that this method can effectively suppress high-frequency oscillations of the reverberation envelope, as well as exhibit robustness and resistance to reverberation interference. [ABSTRACT FROM AUTHOR]

Numerous neuroimaging studies have identified significant individual variability in intertemporal choice, often attributed to three neural mechanisms: (1) increased reward circuit activity, (2) decreased cognitive control, and (3) prospection ability. These mechanisms that explain impulsivity, however, have been primarily studied in the gain domain. This study extends this investigation to the loss domain. We employed a hierarchical Bayesian drift‐diffusion model (DDM) and the inter‐subject representational similarity approach (IS‐RSA) to investigate the potential computational neural substrates underlying impulsivity in loss domain across two experiments (n = 155). These experiments utilized a revised intertemporal task that independently manipulated the amounts of immediate and delayed‐loss options. Behavioral results demonstrated positive correlations between the drift rate, measured by the DDM, and the impulsivity index K in Exp. 1 (n = 97) and were replicated in Exp. 2 (n = 58). Imaging analyses further revealed that the drift rate significantly mediated the relations between brain properties (e.g., prefrontal cortex activations and gray matter volume in the orbitofrontal cortex and precuneus) and K in Exp. 1. IS‐RSA analyses indicated that variability in the drift rate also mediated the associations between inter‐subject variations in activation patterns and individual differences in K. These findings suggest that individuals with similar impulsivity levels are likely to exhibit similar value processing patterns, providing a potential explanation for individual differences in impulsivity within a loss framework. [ABSTRACT FROM AUTHOR]

Gait speed and timed-up-and-go (TUG) predict cognitive decline, falls, and mortality. Dual-tasks may be useful in cognitive screening among people living with dementia (PWD), but more evidence is needed. This cross-sectional study aimed to compare single- and dual-task performance and determine the influence of dementia severity on dual-task performance and interference. Thirty PWD in two residential care facilities (Age: 81.3 ± 7.1 years; Montreal Cognitive Assessment: 10.4 ± 6.0 points) completed two trials of single- (feet apart) and dual-task posture (feet apart while counting backward), single- (walk 4 m) and dual-task gait (walk 4m while naming words), and single- (timed-up-and-go (TUG)), and dual-task functional mobility (TUG while completing a category task) with APDM inertial sensors. Dual-tasks resulted in greater sway frequency, jerk, and sway area; slower gait speed; greater double limb support; shorter stride length; reduced mid-swing elevation; longer TUG duration; reduced turn angle; and slower turn velocity than single-tasks (ps < 0.05). Dual-task performance was impacted (reduced double limb support, greater mid-swing elevation), and dual-task interference (greater jerk, faster gait speed) was related to moderate-to-severe compared to mild PWD. Moderate-to-severe PWD had poorer dynamic stability and a reduced ability to appropriately select a cautious gait during dual-tasks than those with mild PWD, indicating the usefulness of dual-tasks for cognitive screening. [ABSTRACT FROM AUTHOR]

Background: Prescription opioid use (POU) has been shown to lead to cardiovascular disease (CVD), but its association with heart failure has not been well studied. We investigated the potential causal association between POU and HF using cohort studies and Mendelian Randomization (MR) analysis., Methods: Initially, we examined the longitudinal association between POU and HF using the data from the Health and Retirement Study (HRS) and the UK biobank. Next, we employed a two-sample MR analysis using summary statistics from genome-wide association studies (GWAS) to assess the potential causal associations between POU and HF., Results: During a median of 3.8 and 13.8 years of follow-up, there were 441(8.04 per 1000 person-year) and 16,170 (3.96 per 1000 person-year) HF cases in the HRS and the UK biobank, respectively. After adjusting for covariates, participants who used prescription opioids had a 32% increased risk of developing HF, compared with non-users (HR = 1.32, 95%CI: 1.26-1.38, P < 0.001). In the MR analysis, summary statistics for POU were obtained from 78,808 UK Biobank study participants, and summary data for HF were obtained from 218,792 participants of a European population. A causal effect of genetic liability for POU on an increased risk of HF (OR = 1.16, 95% CI = 1.06, 1.27, P = 0.001) was suggested. The results were generally consistent in the sensitivity analysis, and no pleiotropy or heterogeneity were observed., Conclusions: POU is associated with a high risk of HF. Our findings provide new insight into prescription opioid use among populations at risk of heart failure. More studies are needed to validate our results and further investigate the underlying mechanisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Background: A limited number of studies investigated the association between blood pressure variability (BPV) and cognitive impairment in patients with hypertension. This study aimed to identify the longitudinal association between BPV and cognitive decline and the role of blood pressure (BP) control in this association., Methods and Results: Participants with hypertension from the HRS (Health and Retirement Study), the ELSA (English Longitudinal Study of Ageing), and the CHARLS (China Health and Retirement Longitudinal Study) were included. Variation independent of the mean (VIM) was adopted to measure BPV. Cognitive function was measured by standard questionnaires, and a standardized Z score was calculated. Linear mixed-model and restricted cubic splines were adopted to explore the association between BPV and cognitive decline. The study included 4853, 1616, and 1432 eligible patients with hypertension from the HRS, ELSA, and CHARLS, respectively. After adjusting for covariates, per-SD increment of VIM of BP was significantly associated with global cognitive function decline in Z scores in both systolic BP (pooled β, -0.045 [95% CI, -0.065 to -0.029]) and diastolic BP (pooled β, -0.022 [95% CI, -0.040 to -0.004]) among hypertensive patients. Similar inverse associations were observed in patients with hypertension taking antihypertensive drugs and in patients with hypertension with well-controlled BP., Conclusions: High BPV was independently associated with a faster cognitive decline among patients with hypertension, even those with antihypertensive medications or well-controlled BP. Further studies are needed to confirm our results and determine whether reducing BPV can prevent or delay cognitive decline.

Background: Physical activity preserves cognitive function in people without dementia, but the relationship between physical activity and cognitive domains among people living with dementia is unclear., Objective: The objective of this study was to explore the association between physical activity and cognition domains among people living with dementia., Methods: Participants living with dementia in residential care facilities (complete case analysis: n = 24/42) completed a battery of cognitive tests (global cognition: Montreal Cognitive Assessment; executive function: Trail-Making Test, Digit Span Forward Test; perception and orientation: Benton Judgement of Line Orientation Test; language: Boston Naming Test; learning and memory: Rey Auditory Verbal Learning Test; complex attention: Digit Symbol Substitution Test). Participants wore an actigraphy monitor on their non-dominant wrist over seven days. We conducted a linear regression for total physical activity (independent variable) with race (white/black), fall risk (Morse Fall Scale), and the number of comorbidities (Functional Comorbidities Index) as covariates, and cognitive tests as variables of interest., Results: Participants were primarily male (75%), white (87.5%), and 50%had unspecified dementia (Alzheimer's disease: 33%). Greater physical activity was associated with poorer global cognition, better executive function, and better learning and memory (ps <  0.05). Physical activity was not related to visuospatial perception, language, or complex attention., Conclusions: Physical activity may preserve executive function and learning and memory among people living with dementia. Wandering is more common in later stages of dementia, which may explain greater physical activity observed with lower global cognition. Regularly assessing physical activity may be useful in screening and monitoring cognitive changes.